FIG. 1 is a schematic view of a waterproof structure of a conventional ceiling fan when in use. The ceiling fan comprises a seat body 1 and a first sealing ring 2. The first sealing ring 1 covers the top and the peripheral side of the seat body 1. The seat body 1 and the first seal ring 2 are locked to the ceiling. The seat body 1 is connected with a motor housing 4 through a support rod 3. The support rod 3 is connected with an adapter 5. A second sealing ring 6 is provided and locked between the adapter 5 and the motor housing 4. The first sealing ring 2 and the second sealing ring 6 are made of a soft, plastic or rubber material. Through the first sealing ring 2 and the second seal ring 6, the ceiling fan achieves fastening and waterproof effects between the seat body 1 and the ceiling and between the motor housing 4 and the adapter 5.
After the ceiling fan is installed, the user won't regularly check the deterioration of the sealing rings of the ceiling fan. When the first sealing ring 2 and the second sealing ring 6 are used for a long time and are not periodically replaced, the first sealing ring 2 and the second sealing ring 6 may be deteriorated and damaged. As a result, the waterproof function of the ceiling fan is ineffective, and rainwater accumulates in the motor housing. If the first sealing ring 2 and the second sealing ring 6 are damaged, a gap will be generated between the adapter 5 and the motor housing 4. When the ceiling fan is running, the adapter 5 and the motor housing 4 may shake, collide with or disengage from each other to cause a danger. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.